The 5548UP is non-blocking. All 10 Gbps ports can run at wire speed simultaneously. Reference.
There is an internal Unified Port Controller (UPC) ASIC per each group of 8 ports but it does not introduce blocking. Later in the linked document it states:
"The UPC manages eight ports of 1 and 10 Gigabit Ethernet or eight ports of 1/2/4/8-Gbps Fibre Channel. It is responsible for all packet processing and forwarding on ingress and egress ports. Each port in the UPC has a dedicated data path. Each data path connects to UCF through a dedicated fabric interface at 12 Gbps. This 20 percent over-speed rate helps ensure line-rate throughput regardless of the internal packet headers imposed by the ASICs"
